Levelling device

Abstract

A levelling apparatus for use between a structural frame member defining a first plane and a supporting member defining a second plane, vertically adjustable between raised and lowered positions, comprising a base section having first and second inclined surfaces, a top section having first and second inclined surfaces, and first and second pairs of half wedge members disposed intermediate the base and top section, the half wedge members having inclined faces mating with the complementary surfaces formed on the base and top section. A threaded rod is disposed longitudinally within the levelling device, passing through the pairs of half wedges members and brackets engaging the back sides of the half wedge members, with nuts threadingly engaging each end of the threaded rod. Rotation of one or both nuts causes longitudinal translation of the half wedge members and resulting vertical adjustment of the levelling device. The half wedge members are pivotable about lateral pivot pins, so that substantially constant contact is maintained between the top and base section when the base section is tilted due to an inclined support surface. Braces secured to the opposite ends of the pivot pins cooperate with the brackets to prevent lateral displacement of the components. The top section is angularly adjustable relative to the base section to compensate for an uneven support surface.

What is claimed is: 
     
       1. A levelling apparatus for use between a structural frame member defining a first plane and a support member defining a second plane, vertically adjustable between raised and lowered positions, comprising: a base section having a lower surface adapted to rest on said support member, and an upper surface having first and second inclined surfaces;   a top section having an upper surface adapted to support said frame member, and a lower surface having first and second inclined surfaces, said top section being substantially identical to said base section, in inverted orientation,   said top section being angularly adjustable relative to said base section to at least partially compensate for angular misalignment between said first and second planes;   a first pair of half wedge members having front and back sides, disposed intermediate said first inclined surfaces of said base section and said top section, said half wedge members having oppositely inclined top and bottom faces abutting said first inclined surfaces of said top section and said base section, respectively;   a second pair of half wedge members having front and back sides, disposed intermediate said second inclined surfaces of said base section and said top section, said second pair of half wedge members having oppositely inclined top and bottom faces abutting said second inclined surfaces of said top section and said base section, respectively;   first and second brackets engaging said back sides of said first and second pairs of half wedge members, respectively; and   means for longitudinally translating said first and second brackets relative to said top and base sections, said translation effecting longitudinal movement of said half wedge members and consequential vertical adjustment of said levelling apparatus,   longitudinal movement of said first and second pairs of half wedge members causing said top section to move vertically relative to said base section.   
     
     
       2. A levelling device as set forth in claim 1, wherein: said first and second pairs of half wedge members each includes a laterally oriented pivot pin disposed therein, each said pair comprising an upper half wedge member and a lower half wedge member, said upper and lower half wedge members being independently pivotable about their respective pivot pin, whereby   said inclined top faces of said upper half wedge members maintain substantially constant areas of contact with said first and second inclined surfaces of said top section, and said inclined bottom faces of said lower half wedge members maintain substantially constant areas of contact with said first and second inclined surfaces of said base section.   
     
     
       3. A levelling device as set forth in claim 2, wherein: said top section is angularly adjustable relative to said base section to compensate for any angular orientation of said first plane relative to said second plane, such that the upper surface of said top section remains substantially horizontal.   
     
     
       4. A levelling device as set forth in claim 1, wherein said translating means comprises: a threaded rod longitudinally disposed intermediate said half wedge members, having a first end extending through an opening in said first bracket and a second end extending through an opening in said second bracket; and   first and second nuts threadingly engaged on said first and second ends of said rod, whereby tightening and loosening one of said nuts causes said first and second pairs of half wedge members to converge and diverge, respectively.   
     
     
       5. A levelling device as set forth in claim 1, further comprising: means for restricting lateral movement of said first and second pairs of half wedge members relative to said top and base sections.   
     
     
       6. A levelling device as set forth in claim 2, further comprising: a plurality of brace members secured to opposite ends of said pivot pins, said brace members being disposed closely adjacent side portions of said half wedge members and said top and base sections, thereby preventing lateral dislocation of said half wedge members.   
     
     
       7. A levelling apparatus for use between a structural frame member defining a first plane and a support member defining a second plane, vertically adjustable between raised and lowered positions, comprising: a base section having a lower surface adapted to rest on said support member, and an upper surface having first and second inclined surfaces;   a top section having an upper surface adapted to support said frame member, and a lower surface having first and second inclined surfaces, said top section being substantially identical to said base section, in inverted orientation,   said top section being angularly adjustable relative to said base section to at least partially compensate for angular misalignment between said first and second planes;   a first pair of half wedge members having front and back sides, disposed intermediate said first inclined surfaces of said base section and said top section, said half wedge members having oppositely inclined top and bottom faces abutting said first inclined surfaces of said top section and said base section, respectively;   a second pair of half wedge members having front and back sides, disposed intermediate said second inclined surfaces of said base section and said top section, said second pair of half wedge members having oppositely inclined top and bottom faces abutting said second inclined surfaces of said top section and said base section, respectively;   first and second brackets engaging said back sides of said first and second pairs of half wedge members, respectively;   a threaded rod longitudinally disposed intermediate said half wedge members, having a first end extending through an opening in said first bracket and a second end extending through an opening in said second bracket;   first and second nuts threadingly engaged on said first and second ends of said rod, whereby tightening and loosening one of said nuts causes said first and second pairs of half wedge members to longitudinally converge and diverge, respectively, longitudinal movement of said first and second pairs of half wedge members causing said top section to move vertically relative to said base section;   first and second laterally oriented pivot pins disposed intermediate said half wedge members, having opposite ends extending beyond the sides of said half wedge members; and   a plurality of vertical braces secured to said opposite ends of said pivot pins and disposed closely adjacent the sides of said half wedge members and said top and base sections, thereby prohibiting lateral movement of said half wedge members relative to said top and base sections.